Cooling of spark plugs and the like



June 20, 1933* R. CHILTON 1,914940 COOLING 0F SPARK PLUGS AND THE LIKE Filed May 15, 1950 INVENTOR. oLlqNo ;c'1'171:7'01\z Patented June 20, 1933 ROLAND CHILTON, F RIDGEWOOID, NEW JERSEY, ASSIGNOR T0 WRIGHT AEBONAUTIGAL CORFORATION, A CDRPORATIQN 0F NEW YORK C'GOLING 0F SPARK PLUGS AND THE LIKE Application filed may 15,

My invention relates to improvements in cooling internal combustion engine cylinders and associated parts.

Air cooled aviation engines in particular are subject to local hot spots in the combustion chambers which limit the usuable compression ratio and therefore the poweroutput. For example, there isusually a high temperature zone at the spark plugs and ad m jacent combustion chamber wall, particularly in the case of plugs located on the leeward side of an air cooled cylinder head.

The present invention provides additional radiating means for such points without change in the present standardized dimensions of the plugs, which should remain interchangeable between various engine designs.

According to the present invention, an extension in intimate thermal union Withthe cylinder head is disposed about the spark plug to form a base for the application of a substantially increased number and area of cooling fins.

In the preferred form shown in the drawing the extension is indicated as being conveniently 'formed integral with the usual spark plug hole bushing and comprises an enlarged cylindrical extension surrounding the plug and provided with a plurality of integral annular radiating fins.

This cooling element is preferably made of material of high thermal conductivity, i. e., a material characterized by a relatively small temperature gradient, whence it will be seen that the bushing into which the spark plug is screwed will be substantially reduced in temperature, with a corresponding reduction in the temperature of the spark plug itself and of the surrounding cylinder wall.

.Referring now to the drawing-1 is the cylinder wall with its radiating fins 2-2. 3 is the spark plug boss machined to receive the bushing 5. 4 shows a standard spark plug. 5 is the bushing having the integral radiating fins 6, and threaded internally for the sparkplug and externally to fit the cylinder boss, 7 is the cavity to accommodate the spark plug.

5 It will be obvious that alternative disposi- 1930. Serial No. 452,596.

tions of the fins to the specific showing of an== nular radiating elements springing from a cylinder maybe used. Any system providing a large increase in radiating surface in intimate thermal contact with the spark plug bushing or the combustion chamber wall there around being considered within the scope of the invention.

lVhile l have described my invention in detail in its present preferred embodiment, it M will be obvious to those skilled in the art after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. l aim in the appended claims to cover all such modifications and changes.

What ll claim is:

l. A device for cooling the hot spot in the .wall of an engine cylinder in the vicinity of the spark plug and the spark plug itself m comprising an exteriorly finned metallic shell surrounding substantially the entire projecting length of the spark plug, the wall of said shell being wholly independent of and spaced from the structure of the spark plug whereby the latter may be bodily removed and withdrawn without disturbing in any way the connection between said shell and the engine cylinder.

2. A device for cooling the hot spot in the wall of an engine cylinder in the vicinity of i the spark plug and the spark plug itself comprising. an exteriorly finned metallic shell having an exteriorlythreaded bushing and a shoulder around said bushing, both said shell and said bushing being in intimate thermal contact with the cylinder wall; the finned portion of said shell being substantially coextensive with the entire projecting length of the spark plug and being open at its outer end to admit of the spark plug being bodily removed and withdrawn from said shell with-; out disturbing in any way the intimate ther mal contact aforesaid, and said shell having formed therein at its inner end and within said bushing a threaded opening into which the inner end of the spark plug is screwed.

In testimony whereof I hereunto afllx my signature.

ROLAND CHILTON. 9 

